package server;

import org.dom4j.*;
import org.dom4j.io.SAXReader;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.*;

/**
 * Minicat的主类
 */
public class Bootstrap {

    /**定义socket监听的端口号*/
    private int port = 8080;

    private Mapper mapper = new Mapper();

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }


    /**
     * Minicat启动需要初始化展开的一些操作
     */
    public void start() throws Exception {

        // 4.0 加载解析minicat配置 server.xml
        loadServer();

        // 加载解析相关的配置，web.xml
        loadServlet();

        // 定义一个线程池
        int corePoolSize = 10;
        int maximumPoolSize =50;
        long keepAliveTime = 100L;
        TimeUnit unit = TimeUnit.SECONDS;
        BlockingQueue<Runnable> workQueue = new ArrayBlockingQueue<>(50);
        ThreadFactory threadFactory = Executors.defaultThreadFactory();
        RejectedExecutionHandler handler = new ThreadPoolExecutor.AbortPolicy();


        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(
                corePoolSize,
                maximumPoolSize,
                keepAliveTime,
                unit,
                workQueue,
                threadFactory,
                handler
        );



        /*
            完成Minicat 1.0版本
            需求：浏览器请求http://localhost:8080,返回一个固定的字符串到页面"Hello Minicat!"
         */
        ServerSocket serverSocket = new ServerSocket(port);
        System.out.println("=====>>>Minicat start on port：" + port);

        /*while(true) {
            Socket socket = serverSocket.accept();
            // 有了socket，接收到请求，获取输出流
            OutputStream outputStream = socket.getOutputStream();
            String data = "Hello Minicat!";
            String responseText = HttpProtocolUtil.getHttpHeader200(data.getBytes().length) + data;
            outputStream.write(responseText.getBytes());
            socket.close();
        }*/


        /**
         * 完成Minicat 2.0版本
         * 需求：封装Request和Response对象，返回html静态资源文件
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            InputStream inputStream = socket.getInputStream();

            // 封装Request对象和Response对象
            Request request = new Request(inputStream);
            Response response = new Response(socket.getOutputStream());

            response.outputHtml(request.getUrl());
            socket.close();

        }*/


        /**
         * 完成Minicat 3.0版本
         * 需求：可以请求动态资源（Servlet）
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            InputStream inputStream = socket.getInputStream();

            // 封装Request对象和Response对象
            Request request = new Request(inputStream);
            Response response = new Response(socket.getOutputStream());

            // 静态资源处理
            if(servletMap.get(request.getUrl()) == null) {
                response.outputHtml(request.getUrl());
            }else{
                // 动态资源servlet请求
                HttpServlet httpServlet = servletMap.get(request.getUrl());
                httpServlet.service(request,response);
            }

            socket.close();

        }
*/

        /*
            多线程改造（不使用线程池）
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            RequestProcessor requestProcessor = new RequestProcessor(socket,servletMap);
            requestProcessor.start();
        }*/



        System.out.println("=========>>>>>>使用线程池进行多线程改造");
        /*
            多线程改造（使用线程池）
         */
        while(true) {

            Socket socket = serverSocket.accept();
            RequestProcessor requestProcessor = new RequestProcessor(socket, mapper);
            //requestProcessor.start();
            threadPoolExecutor.execute(requestProcessor);
        }

    }

    private void loadServer() throws FileNotFoundException, DocumentException {
        String serverPath = "F:\\lagou-learn\\lagousource\\zuoye\\zuoye-tomcat\\mytomcat\\conf\\server.xml";
        FileInputStream fileInputStream = new FileInputStream(serverPath);
        SAXReader saxReader = new SAXReader();
        Document document = saxReader.read(fileInputStream);
        Element rootElement = document.getRootElement();
        List<Element> serviceList = rootElement.selectNodes("//Server");
        for (Element serviceEle : serviceList) {
            // service
            Mapper.Service service = new Mapper.Service();

            Mapper.Connector connector = new Mapper.Connector();
            Element connectorEle = (Element) serviceEle.selectSingleNode("//Connector");
            Attribute portConf = connectorEle.attribute("port");
            connector.setPort(Integer.parseInt(portConf.getValue()));
            this.setPort(Integer.parseInt(portConf.getValue()));
            service.getConnectorList().add(connector);

            Mapper.Engine engine = new Mapper.Engine();
            List<Element> hostList = serviceEle.selectNodes("//Host");
            for (Element hostEle : hostList) {
                // host
                Attribute nameAttr = hostEle.attribute("name");
                String ip = nameAttr.getValue();
                Attribute appbaseAttr = hostEle.attribute("appbase");
                String appbasePath = appbaseAttr.getValue();

                Mapper.Host host = new Mapper.Host();
                host.setName(ip);
                host.setAppbase(appbasePath);

                List<Element> contextList = hostEle.selectNodes("//Context");
                for (Element contextEle : contextList) {
                    Attribute pathAttr = contextEle.attribute("path");
                    String contextPath = pathAttr.getValue();

                    Mapper.Context context = new Mapper.Context();
                    context.setPath(contextPath);

                    host.getContextList().add(context);
                }
                engine.getHostList().add(host);
            }
            service.setEngine(engine);
            mapper.getServiceList().add(service);
        }
    }




    /**
     * 加载解析web.xml，初始化Servlet
     */
    private void loadServlet() throws IOException {
        for (Mapper.Service service : mapper.getServiceList()) {
            Mapper.Engine engine = service.getEngine();
            for (Mapper.Host host : engine.getHostList()) {
                for (Mapper.Context context : host.getContextList()) {
                    String contextPath = context.getPath();
                    String webapps = "F:\\lagou-learn\\lagousource\\zuoye\\zuoye-tomcat\\mytomcat\\webapps";

                    InputStream resourceAsStream = new FileInputStream(webapps + contextPath + "/web.xml");
                    SAXReader saxReader = new SAXReader();

                    try {
                        Document document = saxReader.read(resourceAsStream);
                        Element rootElement = document.getRootElement();

                        List<Element> selectNodes = rootElement.selectNodes("//servlet");
                        for (int i = 0; i < selectNodes.size(); i++) {
                            Element element =  selectNodes.get(i);
                            // <servlet-name>lagou</servlet-name>
                            Element servletnameElement = (Element) element.selectSingleNode("servlet-name");
                            String servletName = servletnameElement.getStringValue();
                            // <servlet-class>server.LagouServlet</servlet-class>
                            Element servletclassElement = (Element) element.selectSingleNode("servlet-class");
                            String servletClass = servletclassElement.getStringValue();

                            // 根据servlet-name的值找到url-pattern
                            Element servletMapping = (Element) rootElement.selectSingleNode("/web-app/servlet-mapping[servlet-name='" + servletName + "']");
                            // /lagou
                            String urlPattern = servletMapping.selectSingleNode("url-pattern").getStringValue();
                            Mapper.Wrapper wrapper = new Mapper.Wrapper(contextPath + urlPattern, (HttpServlet) Class.forName(servletClass).newInstance());
                            context.getWrapperList().add(wrapper);
                        }
                    } catch (DocumentException e) {
                        e.printStackTrace();
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
                    } catch (InstantiationException e) {
                        e.printStackTrace();
                    } catch (ClassNotFoundException e) {
                        e.printStackTrace();
                    }

                }
            }
        }

    }


    /**
     * Minicat 的程序启动入口
     * @param args
     */
    public static void main(String[] args) {
        Bootstrap bootstrap = new Bootstrap();
        try {
            // 启动Minicat
            bootstrap.start();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
